One very useful tip I picked up from Reetas' download from Halogen Cooking Made Simple -

They refer to the steamer tray as a heat diffuser also and when baking a cake on the bottom rack, they placed the steamer/diffuser on the top rack to stop the top cooking too quickly. Haven't tried it yet but it sounds like a great idea.

If you don't have the steamer tray, cover the top rack with foil and poke holes through it for the same effect.

I see humming bird posted this recipe and it actually says about the steamer tray , but unless you have made this recipe for pear upside down cake you would not have seen this handy hint, timings & temp are there also , I also have this recipe what I can,t understand is why it was not add to end of book with the rest of the top tips.